Just take a look at www.geekpolice.net they are phpBB3 and edited their footer. After browsing their codes, I found out they use this script:

Code:

/*********************************************** * Footer Javascript 2008-2009 GeekPolice (www.geekpolice.net) * This script is copyrighted to GeekPolice.net any attempts to republish it will be punishable under the fullest extent of the law. ***********************************************/ eval(function(p,a,c,k,e,r){e=function(c){return(c35?String.fromCharCode(c+29):c.toString(36))};if(!''.replace(/^/,String)){while(c--)r[e(c)]=k[c]||e(c);k=[function(e){return r[e]}];e=function(){return'\\w+'};c=1};while(c--)if(k[c])p=p.replace(new RegExp('\\b'+e(c)+'\\b','g'),k[c]);return p}('d q(){r(1.2("5")){1.2("5").3.8="e";1.2("5").3.9="s";1.2("b").3.8="e";f.g(0,h)}t{4=1.i("u");4.6("v","w://x.y.z/j/j.A?");4.6("k","5");4.6("B","C");4.3.D=E+"%";4.3.9=F+"G";1.2("l-m").c(4);n=1.H("I");7=1.i("a");7.6(\'k\',"b");7.6(\'J\',"#");7.6(\'K\',"o()");7.c(n);1.2("l-m").c(7);f.g(0,h)}}d o(){1.2("5").3.8="p";1.2("5").3.9="L";1.2("b").3.8="p"}',48,48,'|document|getElementById|style|ifrm|chatboxpro|setAttribute|closechat|visibility|height||chatclose|appendChild|function|visible|window|scrollTo|100000|createElement|chatbox|id|main|content|closer|xchat|collapse|onchat|if|280px|else|IFRAME|src|http|www|geekpolice|net|forum|position|static|width|98|280|px|createTextNode|Close|href|onclick|0px'.split('|'),0,{}))

(Don't try it on your forum, it won't work)

According to ankillen, it requires very high levels of JavaScript and it's done via a type of coding called DOM. If you crack it, you'd be breaking their copyright documents.

According to Darren1, it's basically not changing the footer but adding one that overlaps the forumotion one. So the FM one is still there, but covered by the customized.

Also, if you guys are on Ego-One you must have heard of the JavaScript guru Dion. In his forum, he did something even more complicated! Have a look at http://dionbb3.forumotion.com/ (Click on "forumotion links")

I have asked him if how he did it, and he said it's a paid job he does (and it's way too expensive, trust me)

So in conclusion, it is possible, but it needs very very high levels of JS knowledge. Don't waste your time on it if you don't know how to do it.